A number of human and animal disorders are characterized by excessive cellular exfoliation and/or hyperkeratinization. These conditions include dandruff (Seborrhea sicca), seborrheic dermatitis, acne vulgaris, rosacea, Herpes zoster, psoriasis and eczema, among others. Additional conditions which exhibit excessive exfoliation include various rashes and allergies, including responses to poison oak, ivy and sumac, allergies, chicken pox, insect bites, athlete's foot, actinic keratitis, contact dermatitis, diaper rash, and all forms of pruritis. Various topical formulations are available to alleviate some of the symptoms associated with these conditions.
When the condition is one which affects the scalp, treatment can be carried out via the use of a shampoo. These usually contain a primary detergent, such as a fatty alcohol sulfate, an ether sulfate, a sarconisate or some other anionic material. Additional materials may include aqueous solutions of a soft soap, preservatives, sequestrants, colors, and perfumes. So-called "soapless" shampoos are primarily aqueous solutions of sulfonated oils. Shampoos are used for medicinal purposes because they are easy to formulate and to use, and are generally inexpensive to prepare.
Dandruff, a product of hyperkeratinization, is one condition addressed by special shampoos. These anti-dandruff shampoos or agents generally include ingredients designed to normalize the turnover rate of epidermal cells. Among these ingredients are coal tar, quarternary ammonium compounds, resorcinol, salicylic acid, selenium sulfide, sulfur, undecylenic acid and its derivatives, and zinc pyrithione (i.e., zinc 2-mercaptopyridine N-oxide salt).
An example of the literature on shampoos is U.S. Pat. No. 5,053,222 to Takasu et al., the disclosure of which is incorporated by reference. The patent teaches the various advantages and pitfalls of different anti-dandruff formulations, pointing out that zinc pyrithione, as an antibacterial may; endanger the native ecology of the hair. Formulations of tocopherol esters are stressed, the patent pointing out that many of these are insoluble, do not exhibit long term efficacy, and present difficulty with respect to incorporation in standard formulations.
While many formulations with anti-dandruff efficacy are known, the inventors are unaware of any which incorporate vitamin B12 therein. It has been found, quite surprisingly, that topical formulations which include vitamin B12 therein have an impact on excess exfoliation or hyperkeratinization. In particular, shampoo formulations incorporating vitamins B12 therein have been shown to be effective in alleviating dandruff. This, and other aspects of the invention are set forth in greater detail in the disclosure which follows.